Sen. Charles E. Schumer, D-N.Y., said Monday that states should be allowed to "experiment" with marijuana legalization.
Schumer said he had no problem with New York Gov. Andrew Cuomo's medical marijuana push, while more generally taking a cautious approach to the issue.
"You know, it's a tough issue," said Schumer, who is the number three Democrat in the Senate and no evangelist on the issue, told MSNBC. "We talk about the comparison to alcohol. And, obviously, alcohol is legal, and I'm hardly a prohibitionist, but it does a lot of damage."
Schumer led the charge to ban the chemicals used in synthetic marijuana, which became law in 2012 as part of the Food and Drug Safety and Innovation Act.
"And so, the view I have, and I'm a little cautious on this, is let's see how the state experiments work," Schumer. "We now have the states as laboratories, different states at different levels. Colorado and Washington sort of opened the door."
His comments come after Colorado and Washington passed referenda last year decriminalizing cannabis for recreational use.
Schumer's comments also follow Cuomo's announcement earlier this month that using his administrative powers, the state would begin a pilot medical marijuana program at 20 hospitals. That represents an about face for Cuomo, who previously opposed the issue.
"The governor's proposal in New York" is "much more cautious" than those elsewhere, Schumer noted.
"I'd be a little cautious here at the federal level and see the laboratories of the states, see their outcomes, before we make a decision," Schumer continued.
Asked if the federal government should crack down, Schumer said "No, I think having the states experiment is a good idea."
Schumer's backing of state experimentation is the latest evolution in recent weeks on pot in recent weeks, joining Senate Majority Leader Harry Reid, D-Nev., and others.
Tom Angell, chairman of Marijuana Majority, an advocacy group, said he was pleased to hear Schumer's remarks.
"Sen. Schumer is a longtime advocate of harsh, punitive drug policies, but everyone in Washington, D.C. knows that he's an even bigger advocate of playing smart politics," Angell said. "The polls now clearly show that voters want to move beyond the failure of marijuana criminalization, and savvy politicians like Chuck Schumer have no choice but to follow where the people are leading. This is how federal prohibition ends."